Speed change device



J. D; CHRISTIAN 2,108,367 v SPEED CHANGE DEVICE Filed Nov. 28, 1936 2Sheets-Sheet 1 Feb. v15', 193s.

' l Feb; 15, 1938, J. D. CHRISTIAN SPEED CHANGE DEVICE Filed Nov. 2a,193s 2 Shavers-snee: 2

Patented Feb. 15, 1938 UNITED STATESI PATENT OFFICE SPEED CHANGE DEVICEJoseph D. Christien, sen'rrenelseo, com. Application November 2s, 193s,serial No'. 113,246

solemnv (cl. 'x4-421) Tl'iis'invention relates to a speed Jchangedevice.

In my prior Patent No. 1,860,703, issued Mey 31, 1932, I have discloseda construction of an 5 electric power unit in whichl an electric motoris mounted upon and supported by a speed change unit, the motor and thespeed change unit lbeing mounted together upon a base provided onlybeneath the speed change unit. 'Ihe device of this' patent. met with arecognized commercial success',q and resulted in the advent of what isnow known in the commercial-art as #motorized speed reducers.

Because of the nature of the structure utilized,

the cost of the unit of my aforesaid patent has e been relatively high.This is necessarily so because, for example, to provide such' a unit anelectric motor is rst purchased and reconstructed for reception in thespeed change unit, thev motor shaft being bored or splined to receive adirect connection to a'shaft in the speed reduction unit. This of courseinvolves charges in procuring the customer's motor, in taking down themotor, in either remachining its standard shaft, or else making a newshaft, and in assembling the motor on the reduction unit.

A further objection to units of this type has been encountered in thelack of exibilty in effectlng any speed change in a simple andinexpensive manner. With the motor directly coupled to a sha'ft in thespeed reducing unit,I a change in speed between thev motor and the speedreduction unit .was --n'ot possible. The only change' that couldbeeii'ected, so far as the unit ad itself was concemed, was to take theunit apart and change the gears therein.

. Since this required -removal of the unit from the base upon which itwassupported, and ytaking down of the entire unit, the cost was too highand this .was rarely dne. If it was attempted to secure a ,change ofspeed between the driven shaft and the speed reducing unit, as byproviding'a gear or sprocket and chain drive, it was necessary toprovide elernents of comparatively 45 heavy construction andcomparatively high cost, because of the low speed of operation;

The device of the present invention obviates all of the previouslydiscussed dimclties. It enables a standard motor to be used withoutchanging anything on the motor, withut requiring anyspecial machining orother fitting on the mo,- tor. It also enables a speed change to besecured between the motor and the speed reducing unit,`

a simple and inexpensive chain, a ilat belt, or'V .55 vbelt beingutilized for this. To effect a change in speed, it is only necessary tochange the sprockets or pulleys, a matter of a few moments work, sincenothing need be removed from a base or taken out of alignment. If a Vbelt or fiat belt drive is employed, shock absorbing means are 5provided which will absorb much of the shock of the suddenly appliedload. This feature is one of considerable value, inasmuch asl somediiiiculty was encountered in the previous units of my patent, it beingnecessary to provide a rela- 10 tively rugged base and casing structurefor the speed change unit, as well as gearing and other internalconstruction of high 'service factors, to take the abuse.

It is an object of the present invention to pro- 15 vide animproved andsimplified speed change unit construction.

Another object of the present invention is to provide a device in whichthe speed change unit is carried directly by the device to be driven. 20Thus, in accordance with this invention, if a pump, mill, or other unitis to be driven, the speed change unit is mounted directly upon thepower input shaft of the pump, mill or other unit. i

Another object of the present inventionis to provide a novel speedchange unit, particularly as^to the support therefor. l

Another object of the'present invention is to provide a novel piniongear and sprocket or pulley mounting ang a bearing support therefor.

Another object of the present invention is to provide a novel shockabsorbing means in a speed change unit.

'I'he invention includes other features and ob- 35 jects of advantage,some of which, together with the foregoing, will appear hereinafter,wherein present preferred structures embodying the present invention aredisclosed.

In the drawing accompanying and forming a '40 part hereof:

Figure 1 is a vertical section through a ldevice embodying my invention.

Figure 2 is a section -online 2;-2 of Figure 1. Figure 3 is afragmentaryview of a modinca- 45 tion.

. Figure 4 is a side elevationshowing the unit of this invention incombination with a prime mover. p

In accordance with this invention, I provide a speed 'change unit whichis carried entirely by the structure to which the power is to beimparted. Thus, asf-appears in the drawing, I mount the speed reducerunit indicated generally by numeral Q upon an element." to be rotated.

lupon the shaft' 1 and secured thereto by a key 9 A set screw I2 isemployed to retain the hub in place upon the key.

In accordance with this invention, the speed change unit is mounted uponand supported by the hub, which, as will be noted, is .carried entirelyby the shaft 1. In the unit disclosed, this construction is provided byla ange I4 extending from the hub upon which is mounted a spur gear I6 bymeans of cap screws I'l. This spur gear is driven by a gear I8 carriedupon a shaft I9. Shaft I9 is supported vin ball bearings 2| mounted in aframe structure generally indicated at 22. Mounted upon one end of theshaft I9 is another gear 23, which is meshed with a pinion gear 24.

In accordance with this invention, the housing -.structure 22 issupported upon the driven shaft 1. This is effected by providing abushing 26 upon the hub and providing aninwardly extending flange 21 onthe housing structure 22, so that the housing is rotatably mounted uponthe bearing structure provided by the bushing 26 upon the hub. Uponrotation of the pinion gear 24, gear 23 is driven. This in turn rotatesthe shaft|9 and gear I8,v thus effecting aA driving of the ring gear I6.

Rotation of the housing is resisted, preferably resiliently, so thattorque is absorbed from the driving unit. 'I'his is effected by securingan extension indicated by numeral 28 upon end 29 of the housing.Movement of the extension 28 isA resisted, preferably resiliently as bypositioning rod 5| with a flange 52 thereon -between oppositelysupported rubber blocks 30, as appears in AFigure 2 of the drawing.'I'he -rod 5| is secured as toa support 53 for motor 54.

The housing structure 22 includes a portion 3| Awhichextends about andfits againstthe flange I4 provided upon the hub. Packing means, such asthat indicated at 32, are preferably provided to maintain a tight .oilseal, although other oil seal means can --be provided between the flangeI4 and the portion 3| of the housing.

In accordance with this invention, a novel support means is provided forthe pinons 24. This support means is provided by ball bearings 4| and42. Ball bearings 4| are mounted in the housing structure'22, while ballbearings 42 are 4duced indiameter irrespective of the size -ofk drivenby a suitable prime mover as motor 54 i mounted in a cover 'structureindicated generally by numeral 43, which is attached and tted to theoutside of the housing, being retained in place by screws 44.

The pinion gear is provided upon the central V portion of the member 24,extending between the ball bearings. Member 24 can either be solid, as`

appears in Figure `3, or in sleeve form, as in Figthrough suitable powerv belt .'il.v

In Figure 1 I have shown member 24 as beine transmitting means, as

hollow, and with shaft 'I extending therethrough. This construction isuseful when it is desired to mount the unit upon a line shaft or upo'nsome other piece of equipment when the shaft must extend therethrough.In such a case, having member 24 hollow materially assists in reducingthe diameter thereof, since only a few thousandths of an inch clearanceneed be provided between it and the shaft 1.

In the foregoing disclosure I have dealt only with gearing. It is ofcourse obvious that, instead of gearing, sprockets and chain drives canbe substituted, or even pulleys Aand V belts, if desired, to effect thereduction in speed. However, these are only mechanical equivafents forthe gearing, and accordingly the present claims should be accorded arange of equivalents in this respect, the terms gear and gearing beingemployed herein and in the claims as including these other obviousmechanical equivalents.'

I claim: I y

1. In combination, ya prime mover, a shaft to be driven, a casingstructure having three parall'el wall members therein, a gear having ahub. at least one of said wall members being flanged inwardly within thecasing toward another of said wall members, and supported vfor rotationon said gear hub, means for securing said hub to said shaft to positionand support said casing structure on said shaft, another gear-,a shaftextending into-said casing and carrying said another gear, and bearingmeans in two of the parallel wall members on each side of said anothergear, gearing connecting said gear and said another gear, and meansconnecting said extending shaft and said prime mover.

2. -In combination, a prime mover, a shaft to be driven, a casingstructure having three parallel wall members therein, a gear having ahub, atleast one of said wall members being flanged inwardly within thecasing toward another of said wallmembers, and supported for rotation onsaid gear hub, means for securing'said hub to said shaft to position andsupport said casing' structure on said shaft, another gear, a shaftextending into said casing and carrying said another gear, -saidextending A`shaft being hollow and freely passing lsaivd driven-shaft,bearing means in two oi the parallel wall members on each side of saidanother gear, gearing connectingsaid' gear and said another gear, andmeans connecting said extending shaft and said prime mover.

3. In combination, a prime mover, a shaft to be driven, a casingstructure having three parallel wall members therein, a gear having aflanged hub extending along said shaft and agear face over-hanging atleast a portion of said flanged hub, at least one of said wall membersbeing flanged inwardly withinthe casing toward another of said wallmembers, and supported for rotation on said gear hub beneath saidoverhanging gear face, means for securing said hub to said shaft toposition and support said casing structure on said shaft, another gear,a shaft extending into said casing and-carrying said another gear, andbearing means in two of the parallel wall members on each side-of saidanother gear, gearing connecting said gear and said another geanandmeans connecting said extendingshaft and said prime mover.

- JOSEPH D. CHRISTIAN.

